To determine the mean number of chocolate bars eaten, we follow these steps:
1. Multiply each number of chocolate bars by its corresponding frequency:
- For 3 chocolate bars eaten, we have a frequency of 19.
[tex]\[ 3 \times 19 = 57 \][/tex]
- For 4 chocolate bars eaten, we have a frequency of 6.
[tex]\[ 4 \times 6 = 24 \][/tex]
- For 5 chocolate bars eaten, we have a frequency of 15.
[tex]\[ 5 \times 15 = 75 \][/tex]
2. Calculate the total number of chocolate bars eaten:
[tex]\[ 57 + 24 + 75 = 156 \][/tex]
3. Sum the frequencies:
- The frequencies are 19, 6, and 15.
[tex]\[ 19 + 6 + 15 = 40 \][/tex]
4. Calculate the mean (average) number of chocolate bars eaten:
- The mean is the total number of chocolate bars eaten divided by the total frequency.
[tex]\[ \text{Mean} = \frac{156}{40} = 3.9 \][/tex]
Therefore, the mean number of chocolate bars eaten is [tex]\( \boxed{3.9} \)[/tex].
